This proposal requests a high performance, high throughput MALDI-TOF-MS, a mass spectrometer (MS) that couples matrix-assisted laser desorption/ionization (MALDI) with a time-of-flight (TOF) applications for the instrumentation are (1) Victor J. Hruby, Glucagon Structure- Function Studies; New Modalities for Treatment of Pain and Drug Abuse; Peptide Hormone Structure and Function; Opioid Receptor-Specific Peptides; (2) F. Ann Walker, Structure/Physical Property/Reactivity Relationships in Heme Proteins (Cytochrome Models, Nitrophorins, Arsine Binding to Hemoglobin); (3) John H. Enemark, Structural Models for Molybdoenzymes; (4) Vicki H. Wysocki Surface-induced Dissociation; (5) Jaqueline Gervay, Characterization Studies of the in situ Equilibria Occurring in Colominic Acid Oligomers Targeted for Delivery to the HIV Cell Surface Glycoprotein, gp120, and (6) David F. O'Brien, Selective Polymerization of Specially Designed Reactive Lipids. The access to state-of-the-art, high throughput mass spectrometer to analyze samples not amenable to characterization with the current facility instrument is critical to the maximum productivity and success of these projects. The University, the College of Science, and the Chemistry Department have made a strong commitment to the project by providing recently renovated space for an improved mass spectrometry facility, by staffing the facility with two full time mass spectrometry specialists (Ph.D. and M.S. level) and two graduate student RA positions, and by providing cost sharing in the amount of $75,000.